Video conferencing is an established method of collaboration between remotely located participants. Such systems now enable audio and/or video conferencing of multiple parties over packet-switched networks, such as the Internet. Using these systems, participants may simultaneously transmit and receive audio and/or video data streams. Typically, a conference server receives audio and/or video streams from the various participating sources (cameras, general computer devices such as pc's and laptops, as well as other sources), mixes the streams and retransmits the mixed streams to conference participants appearing from a remote location. At the same time, the conference server receives audio and/or video streams from remote sources and projects them on one or more screens for viewing by locally appearing participants. These video conferencing systems implement software along with a variety of cameras, viewing screens and other audio/video capturing devices.
Most existing video conference systems utilize standard limited perspective video cameras which provide a very narrow field of view to the remote participant. Such cameras can be used effectively for video conferences between individuals. Many systems, for example, employ laptop computers having a single narrow field video camera attached to a flat back projection screen. Each participant sees the other participant on his/her own screen. But using such standard narrow field video cameras to capture multiple participants appearing in a single location can be problematic. For example, using a single standard camera in a conference room or class room with multiple participants makes it difficult for the remote participant to see all locally appearing participants clearly. And locally appearing participants will have to turn their heads away from the camera to communicate with one another. For this reason, several applications built for multiple participants appearing together employ multiple cameras. For example, some video conferencing systems employ a separate camera for each participant. Still, positioning of multiple cameras creates difficulty for those participants appearing together to communicate effectively with one another because they often need to be positioned side-by-side in order to be facing the camera and not in the round as they would be positioned at a conference table where they can easily see one another.
Most existing video conference systems also utilize standard flat display screens for viewing. For individuals appearing remotely, for example, laptop view screens are often utilized. This works reasonably well because individual participants are only communicating with one other remote participant—they don't need to communicate with other participants in a single location. But, in larger conference room or class room settings with multiple participants appearing in a single location, large flat display screens for viewing are often employed at a single location (for example, at one end of the room) for all to see. This is problematic because it requires participants to turn away from one another and toward the display (i.e. viewing) screen to see remotely appearing participants. Dedicated video conferencing centers will often position locally appearing participants side-by-side in front of one or more larger screen displays. This way they are more easily seen by remotely appearing participants, but they tend to have difficulty communicating with one another because they have to turn their heads toward one another to talk or pick up non-verbal gestures. In all, current systems create a very unnatural setting for participants appearing together.
Current video conferencing systems try to alleviate the problems. These systems tend to be expensive because they employ multiple cameras and multiple screens and/or they are difficult to set up. And it is common for many individuals and companies to employ larger dedicated conferencing centers for remote conferencing because the equipment is too expensive to own and/or they do not have the proper space for the equipment in their own offices. Further, video conferencing among multiple participants at a single natural informal setting (such as an outdoor setting) is rarely done because equipment is too heavy to move and carry.
Attempts have been made to utilize a 360 degree camera within video conferencing systems to allow broadcast of images showing multiple participants and/or contextual information to remote participants. For example, U.S. application Ser. No. 10/223,021, discloses a video conferencing system utilizing a 360 degree camera and video controller system which automates the process of determining the current speaker in virtual video teleconference by capturing and transmitting a 360 degree view as well as data suggesting the portion of the relevant 360 degree field of the current speaker. This gives the remote participant the opportunity to choose a preferred selected portion of the 360 degree view provided. The ability to select the view is the primary idea behind that system. While the system allows participants to sit together around a conference table, it still requires that they look away from one another and the camera in order to view the display screen.
Various 360 degree cameras have been deployed to enhance the video images broadcast to the remote user. For example, an omni-directional camera design for video conferencing is disclosed in U.S. Pat. No. 7,298,392 B2. The camera allows for higher pixel resolution to produce clearer images of meeting participants sitting or standing around a conference table or positioned in distant range. The system does not, again, solve the issue of participants having to turn their heads to look at a viewing screen placed at one or other sides of the conference table or room. And the application and camera design is expensive and complex in requiring that multiple images be stitched together before it is transmitted to the remote participant(s).
Attempts have also been made to enhance eye-contact between remote participants by utilizing cameras positioned behind see-through screens to more accurately capture a participant's face and align eye contact between remotely appearing participants. For example, U.S. patent application Ser. No. 11/496,805, discloses such a system employing one or multiple cameras which capture images of a participant through a see-through screen. The system does not account for multiple participants appearing in a single location. The camera is positioned on one side of the screen and the participant on the other. And the system is designed specifically to aid alignment of eyes between remotely appearing participants. There is no accommodation for enhancing communication between multiple participants appearing at a single location.
It is desirable, therefore, to have a video conferencing system which allows the positioning of the viewing screen and video camera such that conference participants may maintain natural eye contact with one another as well as with persons appearing from remote locations.